1 /* 2 * Copyright (c) 1996 John S. Dyson 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice immediately at the beginning of the file, without modification, 10 * this list of conditions, and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Absolutely no warranty of function or purpose is made by the author 15 * John S. Dyson. 16 * 4. This work was done expressly for inclusion into FreeBSD. Other use 17 * is allowed if this notation is included. 18 * 5. Modifications may be freely made to this file if the above conditions 19 * are met. 20 * 21 * $FreeBSD: src/sys/sys/pipe.h,v 1.16 1999/12/29 04:24:45 peter Exp $ 22 * $DragonFly: src/sys/sys/pipe.h,v 1.10 2006/06/10 20:00:17 dillon Exp $ 23 */ 24 25 #ifndef _SYS_PIPE_H_ 26 #define _SYS_PIPE_H_ 27 28 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES) 29 30 #ifndef _SYS_TYPES_H_ 31 #include <sys/types.h> 32 #endif 33 #ifndef _SYS_TIME_H_ 34 #include <sys/time.h> /* for struct timespec */ 35 #endif 36 #ifndef _SYS_EVENT_H_ 37 #include <sys/event.h> /* for struct kqinfo */ 38 #endif 39 #ifndef _SYS_XIO_H_ 40 #include <sys/xio.h> /* for struct xio */ 41 #endif 42 #ifndef _SYS_THREAD_H_ 43 #include <sys/thread.h> /* for struct lwkt_token */ 44 #endif 45 #ifndef _MACHINE_PARAM_H_ 46 #include <machine/param.h> /* for PAGE_SIZE */ 47 #endif 48 49 /* 50 * Pipe buffer size, keep moderate in value, pipes take kva space. 51 * Must be a multiple of PAGE_SIZE. 52 */ 53 #ifndef PIPE_SIZE 54 #define PIPE_SIZE 16384 55 #endif 56 57 #ifndef BIG_PIPE_SIZE 58 #define BIG_PIPE_SIZE (64*1024) 59 #endif 60 61 #if PIPE_SIZE < PAGE_SIZE 62 #error "PIPE_SIZE is too small for this architecture" 63 #endif 64 65 /* 66 * Pipe buffer information. 67 * Separate in, out, cnt are used to simplify calculations. 68 * Buffered write is active when the buffer.cnt field is set. 69 */ 70 struct pipebuf { 71 u_int rindex; /* FIFO read index */ 72 u_int dummy1[3]; /* cache-align */ 73 u_int windex; /* FIFO write index */ 74 u_int dummy2[3]; /* cache-align */ 75 u_int size; /* size of buffer */ 76 caddr_t buffer; /* kva of buffer */ 77 struct vm_object *object; /* VM object containing buffer */ 78 }; 79 80 /* 81 * Bits in pipe_state. 82 */ 83 #define PIPE_ASYNC 0x0004 /* Async? I/O */ 84 #define PIPE_WANTR 0x0008 /* Reader wants some characters */ 85 #define PIPE_WANTW 0x0010 /* Writer wants space to put characters */ 86 #define PIPE_REOF 0x0040 /* Pipe is in EOF condition (read EOF) */ 87 #define PIPE_WEOF 0x0080 /* Pipe is in EOF condition (write shutdown) */ 88 #define PIPE_CLOSED 0x1000 /* Pipe has been closed */ 89 90 /* 91 * Per-pipe data structure. 92 * Two of these are linked together to produce bi-directional pipes. 93 */ 94 struct pipe { 95 struct pipebuf pipe_buffer; /* data storage */ 96 struct kqinfo pipe_kq; /* for compat with select/poll/kq */ 97 struct timespec pipe_atime; /* time of last access */ 98 struct timespec pipe_mtime; /* time of last modify */ 99 struct timespec pipe_ctime; /* time of status change */ 100 struct sigio *pipe_sigio; /* information for async I/O */ 101 struct pipe *pipe_peer; /* link with other direction */ 102 u_int pipe_state; /* pipe status info */ 103 int pipe_rip; /* read uio in-progress */ 104 int pipe_wip; /* write uio in-progress */ 105 u_int pipe_wantwcnt; /* for resize */ 106 struct lwkt_token pipe_rlock; /* rindex locked */ 107 struct lwkt_token pipe_wlock; /* windex locked */ 108 struct lock *pipe_slock; /* state locked (shared w/peer) */ 109 }; 110 111 #endif /* _KERNEL || _KERNEL_STRUCTURES */ 112 #endif /* !_SYS_PIPE_H_ */ 113